GlacialTech Igloo 5710 Silent & PWM
Author: Zahn Funk
Editor: Shawn Knight
Date: 11-12-2007
Provided by: GlacialTech
Discuss: View Comments
Testing / Conclusion

Something I discovered when using the 5710 PWM is that my motherboard must have a glitch in the smart fan control function of the BIOS. I reviewed the manual for instructions on how to setup the PWM feature, and if I'm understanding it correctly I simply want to set the temp levels at which the fan turns off, turns on, begins smart control function, and reaches full speed, with steps in that order. I did this correctly but despite what temperature the BIOS reported as the CPU temp, the PWM fan always ran at the full speed of 2800rpm. I figured out why after I installed a utility called SpeedFan, and it showed that my Temp1 reading was at an indicated 127 C, and that my Temp2 reading was actually the figure shown as the CPU temp in the BIOS. Unfortunately the PWM function appears to work off the Temp1 reading only and thus always ran the fan at full speed. The fan is quite noisy at this rpm. GlacialTech claims a 29dB rating however it seemed much louder to me, possibly because the rest of the fans in my system are all fairly quiet and I am used to the water cooling setup I had been using prior to this.

I'll be comparing the performance of the GlacialTech Igloo 5710 Silent and PWM coolers to the stock AMD heatsink at stock speeds and various levels of overclock. Stock coolers are usually adequate at keeping temps under control at stock speed and voltage, however it's when increasing speed and especially voltage that much higher demands are placed on CPU cooling. To monitor CPU temperature I used a utility called CoreTemp. Rather than rely on motherboard sensors which can vary wildly in their accuracy, the CoreTemp program reads temps directly from the Digital Thermal Sensor embedded in the core of the CPU by the manufacturer. Since my 5200+ X2 Windsor has two cores, two temperatures are reported. I logged the readings over a period of time, then averaged each core individually and used the median value for reporting. To generate load temps I ran two instances of Folding@Home, bringing each core to 100% utilization.

As you can see, the stock AMD cooler is quite capable of keeping things under control at stock speeds. However as voltage and speed increased, temperatures quickly climbed out of control. By the time the CPU exceeded a 20% overclock and .3v over default, the cooler was no longer able to keep things stable and the system crashed at 65 C.

By comparison, the Igloo 5710 Silent performs outstandingly. Although idle temps are never that far from the AMD cooler, it's when under load that the GlacialTech really shines, dropping a respectable 6 C load temp at stock speed and a whopping 15+ C when overclocked. I say plus because remember the AMD cooler allowed the system to crash at 65, who knows how much higher it might have gone? At a maximum of 50 C even under 100% load the 5710 Silent allowed the system to run completely stable, and may even have the potential for more. And all this while generating only a whisper of noise, certainly no more than the stock AMD fan did. Now let's compare the much noisier PWM fan, "stuck" at full 2800rpm speed.

With all that racket you might expect the 5710 PWM to outshine the Silent by a wide margin, however this is not the case. Temperatures remained very close, usually within a degree or two, up to a maximum of 3 C difference at the highest overclock. Certainly 3 is nothing to sneeze at however since both coolers allowed the system to run perfectly happy at this level of overclock, that extra bit of cooling just doesn't seem worth the noise. Granted every setup is going to be different, and on a system where the PWM function actually works, the 5710 PWM is probably quite silent as well at lower temps, and the extra bit of performance is there if needed when things start to get hot.


For not knowing who GlacialTech was before I began this review, I came out thoroughly impressed. The Igloo 5710 heatsink is light weight and very well made. The design is similar to other proven tower configurations and allows for a variety of mounting options with the fan, even the addition of a second. The Silent model lives up to its name, running extremely quietly, inaudible when mixed in with other case noise. The PWM version provides slightly better cooling at the expense of more noise, however as long as your motherboard PWM function works correctly, this should only be a factor when high temperatures are reached.

I was a bit leery of the AMD mounting setup, as mentioned previously there is quite a bit of force needed to get the screws started and this force is applied at an angle that would probably damage an unprotected core. However with the IHS that all A64 chips have, the pressure from the heatsink base is distributed across the surface and should not cause any problems. I performed the installation twice, once for the Silent and once for the PWM, even though the fans are the only difference between the two. On Intel configurations, the plastic push-pin style attachment appears to be far more simple and possibly less stressful for the processor. In either case, removal of the fan will greatly assist the installation although this will require a small phillips screwdriver which not everyone may have. On the other hand, unlike many other large tower CPU coolers, the Igloo 5710 does not require its own back plate, so the extra step of removing the motherboard can be eliminated.

At the time of review I was not able to find a US online retailer that carries the Igloo 5710. In fact there are not many that sell any of GlacialTech's products, which makes finding one of these awesome coolers downright difficult. That is a shame too, because the performance is right on par with other big-name, expensive heatsinks. Judging by the price of their other coolers, which all seemed to be in the sub-$10 to $20 range, the Igloo 5710 would be an outstanding value for your dollar. They could definitely do better at marketing and distributing their product though.

Thanks to GlacialTech for providing us with the Igloo 5710 Silent and PWM for review.

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